Scalable Synthesis of Triple‐Core–Shell Nanostructures of TiO2@MnO2@C for High Performance Supercapacitors Using Structure‐Guided Combustion Waves

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2018-03, Vol.14 (11), p.n/a
• Main Authors: Shin, Dongjoon, Shin, Jungho, Yeo, Taehan, Hwang, Hayoung, Park, Seonghyun, Choi, Wonjoon
• Format: Article
• Language: English
• Subjects: Capacitance; Carbon; carbon coating; combustion synthesis; Core-shell structure; core‐shell nanoparticles; Deformation; Electrode materials; Electrodes; Manganese dioxide; metal oxides nanostructures; Nanoparticles; Nanostructure; Nanotechnology; Supercapacitors; Synthesis; Titanium dioxide; Titanium oxides
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201703755

Core–shell nanostructures of metal oxides and carbon‐based materials have emerged as outstanding electrode materials for supercapacitors and batteries. However, their synthesis requires complex procedures that incur high costs and long processing times. Herein, a new route is proposed for synthesizing triple‐core–shell nanoparticles of TiO2@MnO2@C using structure‐guided combustion waves (SGCWs), which originate from incomplete combustion inside chemical‐fuel‐wrapped nanostructures, and their application in supercapacitor electrodes. SGCWs transform TiO2 to TiO2@C and TiO2@MnO2 to TiO2@MnO2@C via the incompletely combusted carbonaceous fuels under an open‐air atmosphere, in seconds. The synthesized carbon layers act as templates for MnO2 shells in TiO2@C and organic shells of TiO2@MnO2@C. The TiO2@MnO2@C‐based electrodes exhibit a greater specific capacitance (488 F g−1 at 5 mV s−1) and capacitance retention (97.4% after 10 000 cycles at 1.0 V s−1), while the absence of MnO2 and carbon shells reveals a severe degradation in the specific capacitance and capacitance retention. Because the core‐TiO2 nanoparticles and carbon shell prevent the deformation of the inner and outer sides of the MnO2 shell, the nanostructures of the TiO2@MnO2@C are preserved despite the long‐term cycling, giving the superior performance. This SGCW‐driven fabrication enables the scalable synthesis of multiple‐core–shell structures applicable to diverse electrochemical applications. A scalable synthesis using structure‐guided combustion waves enables the facile fabrication of multiple core‐shell TiO2@MnO2@Carbon nanoparticles which originate from incomplete combustion inside chemical‐fuel‐wrapped nanostructures. TiO2@MnO2@Carbon‐based electrodes exhibit a greater specific capacitance, and capacitance retention while the absences of MnO2 or carbon shells reveal severe degradation.